Improved screw-cxttting die



tnted peintes JAMES MORSE, OF ENGLEWOOD, NEW JERSEY.

Letters Patent No. 95,371, dated September 28, 1869.

IMPROVED SCREW-CUTTING DIE.

Th'e Sshedule referred to in :these Letters Patent and makingpart of the 'same To all whom 'it may concern Be it known that, I, JAMES O. MORSE, of Englewood, in the county of` Bergen, and State of New Jersey, have invented a new and useful Improvement in Dies for Cutting Screws; andI do hereby declare that the following is afull, clear, and exact description thereof', and of its mode or manner of operation, reference being had to the accompanying drawings, and to the letters of reference 4marked thereon, and making a part of this specification, in which- Figure l is a plan View of my improved die;

Figure 2, a section through the line in fig. l

Figure 3, a separate view of one of the cutters; and

Figure 4, a separate view of one of the thin plates used for settin g out the cutters, as hereafter explained.

My improvement consists essentially iu the use of separate cutters, so formed that they may be conveniently placed and fastened in a cast frame, and readily removed therefrom, and changed orireplaced'a't pleas; ure, having, at the same time, a positive bearing upon the frame, with the cutting-edges at their proper dis' vtance from the axis of revolution, and the cuttingpoints following each other in a true spiral, so that when placed and fastened, the tool is ready for work, without special adj ustment.

The frame A is a single casting, which may be ce'ntred upon and secured to a stock by any appropriate means. Bolts, passing through the two holes shown in fig. 1, will be sufficient.

` Across its inner edge are cut the deep mortises B, to which the base or body-portion a of the cutters C, fig. 3, is accurately fitted,`

From the base of each cutter proceeds a shank or spindle, b, terminating in a screwed end,to which is fitted a nut, n..

From the bottom of the mortises B holes are drilled through to theback of the frame, in which the spindles b are entered. By means of the nuts a, thecutters Ovfare then brought to and secured in a solid bearing upon their seats in the mortises B.

-The cutters are made in sets, of the number required for the tool, generally four or more. They are shaped and fitted as blanks, are then made fast in their places in the frame, and have the thread out upon them, after which they are hardened and tempered.

Any required number of duplicate sets may be made with great facility and perfect accuracy, so that when one set becomes dull, and requires to be sharpened, or for any other reason needs to be changed, it is the work but of a moment to take it out and put in another, which is.at once ready for use, without further adjustment spindles l), between the bases of the cutters and their seats, or by any equivalent means, after which the nuts u may be screwed up and the recutting done, leaving the renewed edge at its original distance from the axis of revolution.

The same frame may be used for cutting screws of different diameter and pitch, within a moderate range of variation, by fitting to it sets of cutters adapted to each; but the frames cost so little, that I have found it much betterjin practice to have a separate one for each diameter of screw.

The advantages of separate cutters, set in a cast frame, as compared with the solid die, if attainable without the drawbacks which have heretofore accompanied them, are sufficiently obvious.

Cast-iron is, substitutedfor steel, in all but the small portion of the whole material included in the cutters. Clearance for the cuttings is obtained in the casting by' giving it the shape required for that purpose,- Which, by the old method, must be worked out with the file in the solid steel. In the difficult and delicate process of tempering, four very small and thin pieces of metal take the place of a single mass, so large and thick that it can rarely be tempered alike in all its parts, or exactly as it ought to be in any part, and a tool that can be repaired and rcfitted any number of times, at tiifling expense, is substituted for one which,

when worn or injured to a certain degree, either cannot be repaired at`all, or only at a cost about equal to that of making a new one, and while the improved tool thus costs less, alike to make it and to keep it in order, in its superior convenience and facility of use it has such advantages that it would be good economy to use it even if it cost moreinstead of' less.

I do not, however, claim as new, either the vcast frame or the separate cutters, in themselves, and independently of the particular method and arrangement in whichuI have combined them. On the contrary, I am well aware that both have been in common use, in several different forms. Those different forms may, however, all be reduced to two: the first, that in which the cutters have been placed in fixed bearings, on the inner edge of' the frame, determining positively the distance of the cutting-edges from the axis of revolution, but with no provision, so far as I have known, for adjustment or exchange of cutters, except -by repeating, in each instance, the original process of fitting, cutting the thread, hardening, and

tempering; the second, that in which they have had their bearings against adjusting-screws, by means of which they are pushed up to the proper distance from the centre-an adjustment which is necessarily destroyed whenever the screws are withdrawn, to allow of the renoval of a cutter, or for any other purpose.

Inl this latter method, therefore, there must be a rcyof the benefit of the machinery and power.

adjustment as often as any change is made, and when changes are frequent, inasmuch as there are generally at least four cutters in a set, all of which must be changed and regulated when one is, the process will involve a great waste of the workmans time, and loss More over, the usual form of the tool by which this possibility of adjustment is obtained, is a peculiarly-complcated and expensive one.

The peculiarity of my invention is that it combines, with the fixed bearings and positive relations to the centre, belonging to the first method, the facility of taking out and replacing the cutters, characteristic of the second, while at the same time it avoids the necessity for special readjustment after every such change.

I get facility of Itaking out and replacing by means of the bolt-nut on the end of the spindle l, coupled, at the same time, with'a certainty that whenever a cutter is pnt in and brought to its place, its cuttingedge will Icome to the precise position'in which it was first formed, and in whichA the work of the tool, Whether by the same cutter or by any duplicate of it, has ever since been done; butin so doing, I depend on the action of the screw, o'r its equivalent, not, as in the case of the adj usting-'screws already referred stantially as described.

2. In combination with the rim or frame A, the outters C, constructed substantially as described, that is, with a body-portion, a, by means of which the cutter is fitted to its seat, and a spindle, b, and nut n, or other equivalent and easily-removable fastening, by means of which it is secured in its place upon the frame.

JAMES O. MORSE.

Witnesses:

Jos. G. E: LARNED, Earn BONIN'.

to, to .make a variable adjustment, which must `be position by screws, or other equivalent means, sub-` 

